单室无膜空气阴极微生物燃料电池处理沼液的研究

摘要

构建了空气阴极无膜微生物燃料电池(microbial fuel cells，MFCs)，以石墨毡作为阴阳极材料，以玉米秸秆厌氧发酵沼液为底物，考察了MFCs的产电性能。结果表明：以沼液为底物的MFCs可连续产电。在一定范围内，输出功率与底物浓度的关系符合莫诺方程，最大功率密度为(271±23) mWm2，约为处理醋酸钠废水时的61%((444±27)阶级mWm2)，内阻大小为53~150Ω，与发酵时物料浓度成反比，与发酵时间成正比；MFCs处理沼液的平均库伦效率为(10±1)%，约为处理醋酸钠时的一半((20±2)%)；底物的COD去除率为88%~92%，其中挥发性有机酸(VFA)的去除率大于96%。实验表明利用MFCs处理沼液是可行的，沼液中难降解颗粒和复杂有机物的水解作用导致MFCs功率密度及库伦效率相对较低，但未影响COD去除。%Air-cathode membrane-free microbial fuel cells (MFCs) operating in continuous mode and with graphite felt cathode and anode were constructed, The electricity production of MFCs using biogas slurry as substrate obtained during anaerobic fermentation of corn stover was investigated. The results show that:MFCs can produce electricity continuously and the relationship between output power and substrate concentration is consistent with Monod equation within a certain range. The maximum power density of MFCs is (271±23) mWm2, which is equivalent to approximately 61%of that obtained from the MFCs((444±27) mWm2) using sodium acetate as substrate. The value of the MFCs internal resistance (53~150Ω) is inversely proportional to the concentration of fermentated material and proportional to the time of fermentation. MFCs treating biogas slurry can have average coulomb efficiency of (10 ± 1)%, which is about the half of that obtained by using the sodium acetate ((20 ± 2)%) as substrate. Chemical oxygen demand (COD) removal of MFCs is approximately 90%, and its removal efficiency of volatile organic acids (VFA) is greater than 96%. Experiments show that using MFCs to treat the biogas slurry is feasible, and the difficult degradable particles and hydrolysis of complex organic compounds in the slurry will lead to cause the MFCs to have relatively low power density and coulombic efficiency, but they do not affect the COD removal.